Quartile histogram assessment of glioma malignancy using high b‐value diffusion MRI with a continuous‐time random‐walk model. (4th February 2021)

• Record Type: Journal Article
• Authors: Karaman, M. Muge; Zhang, Jiaxuan; Xie, Karen L.; Zhu, Wenzhen; Zhou, Xiaohong Joe
• Is Part Of: NMR in biomedicine. Volume 34:Number 4(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-02-04
• Subjects: continuous‐time random‐walk model -- glioma -- high b‐value -- histogram analysis -- intravoxel heterogeneity -- non‐Gaussian diffusion‐weighted imaging; Nuclear magnetic resonance -- Periodicals; Magnetic Resonance Spectroscopy -- Periodicals; 574
• DOI: 10.1002/nbm.4485
• Languages: English
• ISSNs: 0952-3480

Abstract

Abstract : The purpose of this study is to investigate the feasibility of using a continuous‐time random‐walk (CTRW) diffusion model, together with a quartile histogram analysis, for assessing glioma malignancy by probing tissue heterogeneity as well as cellularity. In this prospective study, 91 patients (40 females, 51 males) with histopathologically proven gliomas underwent MRI at 3 T. The cohort included 42 grade II (GrII), 19 grade III (GrIII) and 29 grade IV (GrIV) gliomas. Echo‐planar diffusion‐weighted imaging was conducted using 17 b ‐values (0–4000 s/mm 2 ). Three CTRW model parameters, including an anomalous diffusion coefficient D m, and two parameters related to temporal and spatial diffusion heterogeneity α and β, respectively, were obtained. The mean parameter values within the tumor regions of interest (ROIs) were computed by utilizing the first quartile of the histograms as well as the full ROI for comparison. A Bonferroni–Holm‐corrected Mann–Whitney U‐test was used for the group comparisons. Individual and combinations of the CTRW parameters were evaluated for the characterization of gliomas with a receiver operating characteristic analysis. All first‐quartile mean CTRW parameters yielded significant differences ( p ‐values < 0.05) between pair‐wise comparisons of GrII ( D m : 1.14 ± 0.37 μm 2 /ms; α : 0.904 ± 0.03, β : 0.913 ± 0.06), GrIII ( D m : 0.88 ± 0.21 μm 2 /ms; α : 0.888 ± 0.01, β : 0.857 ± 0.06) and GrIV gliomas ( D m : 0.73 ± 0.22 μm 2 /ms; α : 0.878 ± 0.01; β : 0.791 ± 0.07). The highest sensitivity, specificity, accuracy and area‐under‐the‐curve of using the combinations of the first‐quartile parameters were 84.2%, 78.5%, 75.4% and 0.76 for GrII and GrIII classification; 86.2%, 89.4%, 75% and 0.76 for GrIII and GrIV classification; and 86.2%, 85.7%, 84.5% and 0.90 for GrII and GrIV classification, respectively. Quartile‐based analysis produced higher accuracy and area‐under‐the‐curve than the full ROI‐based analysis in all classifications. The CTRW diffusion model, together with a quartile‐based histogram analysis, offers a new way for probing tumor structural heterogeneity at a subvoxel level, and has potential for in vivo assessment of glioma malignancy to complement histopathology. Abstract : In this study, we demonstrate the feasibility of using a continuous‐time random‐walk (CTRW) diffusion model, together with a quartile histogram analysis, to probe the structural heterogeneity of different grades of glioma and assess their malignancy. Our results have shown significant differences in CTRW parameters either individually or jointly among the three glioma grades. In addition, quartile‐based analysis produced a higher accuracy and a larger area under the ROC curve than the full ROI‐based analysis in all classifications. Collectively, our results suggest a new avenue to tackling the long‐standing problem of imaging‐based, non‐invasive assessment of glioma malignancy.